The Geochemistry of Natural Waters

Transcription

1 The Geochemistry of Natural Waters Surface and Groundwater Environments Third Edition James I. Drever University of Wyoming Prentice Hall Upper Saddle River. NJ 07458

2 Contents 3 Preface xi 1 The Hydrologie Cycle 1 Composition of Rainwater 3 Hydrology 6 Groundwater 9 Groundwater as a Resource and Groundwater Contamination 11 Nonmeteoric Types ofwater 12 Chemical Terms in Hydrology 13 Suggested Reading 13 2 Chemical Background 15 Units and Terminology 15 Equilibrium Thermodynamics 17 Equilibrium Constant 19 Measurements of Disequilibrium 24 Activity-Concentration Relationships 26 Activities of Ionic Species 27 Complex Formation 34 Apparent Equilibrium Constants 35 Computer Codes 36 Review Questions 37 Suggested Reading 40 The Carbonate System and ph Control Carbonic Acid System 41 Alkalinity and Titration Curves 45 Alkalinity Titration 47 Gran Plots iii

3 iv Contents 4 Calcium Carbonate Solubility 52 Dolomite 58 High-Magnesium Calcite 59 Ground and Surface Waters in Carbonate Terrains 60 Review Questions 67 Suggested Reading 68 Clay Minerals and Cation Exchange Mineralogy and Composition 69 Brucite [Mg(OH}zl and Gibbsite [Al(OH)3l 69 Kaolinite and Related Minerals 71 2: 1 Clay Minerals 74 Chlorite 77 Mixed-Layer Clays 78 Sepiolite and Palygorskite 79 Colloid Properties 79 The Double Layer 80 Membrane Filtration 81 Ion Exchange 82 Review Questions 85 Suggested Reading Adsorption 87 Empirical Equations 87 Linear Distribution Coefficient 88 Freundlich Isotherm 89 Langmuir Isotherm 89 Surface Complexation 90 Acid-Base Equilibria 92 Adsorption of Metal Cations 97 Adsorption of Anions 98 The Electric Double Layer 99 Modeling Adsorption with MINTEQA2 102 Review Questions 104 Suggested Reading Organic Compounds in Natural Waters 107 Natural Organic Matter 107 Structure of Natural Organic Solutes 108 Functional Groups 109 Humic Substances 113 Dissolved Organic Carbon (DOC) in Natural Environments 118

4 Contents v Organic Pollutants 119 Solubility and Related Properties 121 Adsorption 122 Biodegradation and Bioremediation 125 Review Questions 126 Suggested Reading Redox Equilibria 129 The Standard Hydrogen Electrode and Thermodynamic Conventions 130 Use of Eh as a Variable 133 Use of pe as a Variable 134 Definition of pe and Eh by Redox Pairs 135 Measurement ofeh 136 Redox Calculations Using WATEQ4F 136 pe-ph and Eh-pH Diagrams 137 System Fe-Q-HzÜ 137 System Fe-O-Hzü-COz 144 System Fe~O-HzO-S 148 Eh-pH Diagrams 152 Partial Pressure or Fugacity-Fugacity Diagrams 154 Review Questions 156 Suggested Reading Redox Conditions in Natural Waters Photosynthesis 159 Respiration and Decay 160 Redox Buffering 162 Lakes 166 The Ocean 169 Groundwater 171 Summary 174 Review Questions 174 Suggested Reading Heavy Metals and Metalloids 175 Sources of Heavy Metals 175 Speciation 177 Organie Matter and Complex Formation 177 Equilibrium Solubility Control 179 Solubility in Redox Reactions 180 pe-ph and Eh-pH Diagrams 182 Roll-Front Uranium Deposits 184

5 Adsorption and Coprecipitation Controls 185 Adsorption by Hydrous Iron and Manganese Oxides 186 Adsorption by Silicates and Carbonates 188 Adsorption by Solid Organie Matter 188 Uptake by Living Organisms 188 Behavior of Specific Elements 189 Copper, Zinc, Cadmium, and Lead 189 Arsenic and Selenium 192 Chromium 194 Mercury 195 Summary 195 Review Questions 196 Suggested Reading Stability Relationships and Silicate Equilibria Solubility Equilibria (Congruent Solution) 197 Solubility of Magnesium Silicates 199 Solubility of Gibbsite 200 Solubility of Aluminosilicates 203 Incongruent Solution and Stability Diagrams 204 Uncertainty in Mineral Stability Diagrarns 210 Review Questions 213 Suggested Reading Kinetics Nucleation 217 Dissolution and Growth 218 Surface Reaction Mechanisms 220 Diffusion Control 220 Dissolution of Calcite in Seawater 221 Growth of Calcite and Aragonite in Seawater 223 Dissolution of Silicates 225 Effect of Solution Composition on Dissolution Rates 228 Relative Dissolution Rates of Different Minerals 232 Comparisons Between Laboratory and Field Dissolution Rates 232 Review Questions 233 Suggested Reading 234 Weathering and Water Chemistry 235 Soil Formation 235 The Mass-Balance Approach to Catchment Processes and Mineral Weathering Reactions 236 Catchment Processes 236 Mineral Weathering Reactions 240 Mass-Balance Calculations in Groundwater Systems

6 Contents vii The Thennodynamic Approach tu Mineral Weathering Reactions 246 The Statistical Approach 251 Case Studies 255 Mackenzie River System, Canada 255 Amazon and Orinoco River Systems 257 Absaroka Mountains, Wyoming 262 Mattoie River, Califomia 269 Cascade Mountains, Washington; Loch Vale, Colorado 269 Adirondack Mountains, New York 275 Waters from Ultramafic Rocks 279 Rhine River 280 Summary 282 Thermodynamic Controls on Clay Mineral Formation 282 Environmental Factors and Water Chemistry 283 Review Questions 287 Suggested Reading Acid Water 289 Acidity and Alkalinity 289 Solubility ofaluminum Hydroxide 291 Acid Deposition 292 Cation Exchange 293 Anion Mobility and Anion Exchange 295 Processes Affecting Sulfate Mobility 296 Biological Processes 297 Chemical Weathering 299 Integrated Models 301 Environmental Effects 305 Acid Mine Drainage 306 Prediction of Acid Generation 308 Prevention of Acid Generation 308 Review Questions 309 Suggested Reading Isotopes 311 Stable Isotopes 311 Fractionation Processes / 16 0 and DIR C/12C S/32S N/ 14N 321 Radioactive Isotopes 322 Tritium C 322

7 Chlorine Radon Radiogenie Isotopes: Strontium Review Questions 325 Suggested Reading Evaporation and Saline Waters Evaporation of Sierra Nevada Spring Water 327 Chemical Divides and the Hardie-Eugster Model 329 Modifications of the Hardie-Eugster Model 332 Magnesium Carbonate Formation 332 Sulfate Reduction and Sulfide Oxidation 334 Ion Exchange and Adsorption 334 Cyclic Wetting and Drying 335 Examples 336 Lake Magadi Basin, Kenya 336 Teels Marsh, Nevada 340 Evaporation of Seawater 343 Persian Gulf Sabkhas 345 Saline Formation Waters 348 Summary 350 Review Questions 351 Suggested Reading 351 Transport and Reaction Modeling 353 The Advection-Diffusion Equation 353 Advection 356 Diffusion and Dispersion 356 Chemical Reaction and Retardation 364 Reaction Path Modeling 368 Application to Contaminant Transport in Groundwater 374 Chemical Evolution of Groundwater 377 Review Questions 378 Suggested Reading 379 Reterences 381 Glossary ot Geological Terms 403 Appendix I Piper and Stift Diagrams 409 Appendix 11 Standard-State Thermodynamic Data tor Some Common Species 413

8 Contents ix Appendix 111 Equilibrium Constants at 25 C and Enthalpies of Reaction for Selected Reactions 419 Answers to Problems 423 Author Index 426 Subject Index 431